Fatty liver
Steatosis, or fatty liver, is the accumulation of triglycerides and other fats in liver cells. In severe fatty liver, fat constitutes as much as 40% of the liver’s weight (as opposed to 5% in a normal liver); the liver’s weight may increase from 3.3 lb (1.5 kg) to as much as 11 lb (5 kg).
Minimal fatty changes are temporary and asymptomatic; severe or persistent changes may cause liver dysfunction. Fatty liver is usually reversible by simply eliminating the cause. (See Reversing fatty liver, page 318.) This disorder may result in recurrent infection or sudden death from fat emboli in the lungs.
Causes
The most common cause of fatty liver in the United States and Europe is chronic alcoholism, with the severity of liver disease directly related to the amount of alcohol consumed. Other common, non-alcohol-related causes include acquired immunodeficiency syndrome, drug toxicity, and pregnancy.
Other causes include malnutrition (especially protein deficiency), obesity, diabetes mellitus, jejunoileal bypass surgery, Cushing’s syndrome, Reye’s syndrome, carbon tetrachloride intoxication, prolonged total parenteral nutrition (TPN), and DDT poisoning.
Whatever the cause, fatty infiltration of the liver probably results from mobilization of fatty acids from adipose tissues or from altered fat metabolism.
